Degussa Aktiengesellschaft

Degussa Gmbh

Pku Pulverkautschuk Union Gmbh

Udo Gorl

Siegfried Wolff

Reinhard Stober

Robert Kuhlmann

Heinz Esch

Ralf Rausch

Ulrich Deschler

Karl Meier

Uwe Ernst

Hans Deusser

Hartmut Lauer

Georg Hellwig

Christoph Klatte

The invention relates to a process for the preparation of finely divided rubbers (rubber powders) by precipitation from aqueous mixtures, which comprise filler in the form of suspensions, water-soluble salts of a metal of groups IIa, IIb, IIIa and VIII of the periodic table of the elements arid a rubber latex (polymer latex), aqueous emulsions of a rubber or rubber solution, in which one or more organosilicon compound(s) containing at least one alkoxy group is or are dissolved or emulsified, optionally in the presence of a surface-active substance, in water, or the compounds mentioned are mixed directly, optionally with a surface-active substance, with an aqueous suspension of an oxidic or silicatic finely divided filler or a mixture of these fillers at a temperature of 10 to 60&deg; C., preferably at room temperature, while stirring, the amount of this mixture envisaged for incoporation in the rubber, based on the filler content, in general being divided into two batches.

Pulverulent rubber powders comprising modified fillers, processes for their preparation and their use

A precipitated silica with the following physicochemical properties:

Precipitated silicas

Bis(2,4-organylthio-s-triazine-6-yl) polysulfides of the general Formula (I) ##STR1## prepared from compounds of the general formula (II) ##STR2## and from an ammonium or alkali polysulfide and the use of such compounds as accelerators in vulcanizable rubber mixtures.

Vulcanizable rubber mixtures containing

Carbon black is reacted with at least one organosilicon compound of the General Formula

Carbon blacks modified with organosilicon compounds, method of their

A method of granulating resorcinol/silica mixtures which comprises transporting a mixture of resorcinol and precipitated silica by conveyor worms to two pressing rollers whose shafts are attached vertically above one another and whose contact pressure can be varied, compacting said mixture between said rollers, breaking up the compacted mixture with a cake breaker to obtain a granulate with minimum grain size and separating the remaining dusty portion of said mixture. The mixtures can be added to vulcanizable rubber to provide improved adhesion to rubber reinforcements.

Method of granulating resorcinol/silica mixtures, the granulates

A two-stage method for the surface modification of natural or synthetic, oxide or silicate fillers using organosilicon compounds of the formulas:

Growing community of inventors

Meckenheim, Germany

Udo Gorl